Existing electronic cigarettes usually comprise a battery stick, a vaporizer and a mouth piece, wherein the vaporizer and a casing tube of the vaporizer are designed as an integral one-piece construction that has to be integrally replaced with a new one when cigarette liquid in the vaporizer is exhausted, which increases the costs for the manufacture and use of the vaporizer. In addition, the vaporizer and the battery stick are usually connected via a twist-lock connection structure or snap-fit connection structure, such connection structures are complicated and are thus inconvenient for the disassembly and replacement of the vaporizer, which worsens the user experience.